Poly-D-lysine（MW: 150000-300000）

Poly-Lysine is an amino acid polymer with a positive charge that can bind to DNA, erythrocyte membrane, or any negatively charged protein. Its main role is in promoting cell adhesion to solid substrates. The mechanism of action involves enhancing the electrostatic interaction between the negatively charged ions on the cell membrane surface and the substrate's surface, such as a cell culture dish or a glass slide. By being adsorbed onto the culture surface, polylysine increases the number of cationic binding sites available for cell binding. The molecular weight of polylysine affects its viscosity, with lower molecular weights resulting in lower viscosity and higher molecular weights leading to higher viscosity, which provides more adhesion sites. For promoting cell adhesion to a solid matrix, polylysine with a molecular weight greater than 30,000 is recommended. There are two common subtypes of poly-lysine, D- and L-. Since poly-lysine is a nonspecific adhesion factor for cell binding, both subtypes can be used as a coating on solid matrices to promote cell growth in cell culture. Poly-D-Lysine with a molecular weight of 30,000-70,000 is suitable for cell culture. The recommended dosage for use as a cell culture substrate is 0.1mg/mL of poly-lysine solution, with approximately 0.5mL-1.0mL used for a 25cm2 culture plate.

1. Storage liquid preparation
A 10mg powder was dissolved in 2mL of sterile deionized water. After filtering and debacterializing with a 0.2μm low-protein adsorbed membrane, a 5mg/mL Poly-D-Lysine storage solution was obtained, which is suitable for cell culture. To avoid contamination from repeated use, the storage solution can be divided into sterile tubes for single use and stored at 4° C or -20° C for at least 1 year. Ensure the solution is based on the original information.
2. Coating substrate for cell culture
To perform cell-related coating experiments using polyD-lysine, it is necessary to optimize the coating conditions for different cell lines and applications. The process generally involves the following steps.
To prepare the coating solution for your experimental system, dilute the storage solution of Poly-D-Lysine with sterile tissue culture grade water or PBS. The ideal coating concentration can be achieved by diluting the solution to 0.1mg/mL, which is approximately 50 times the concentration of the storage solution. It is recommended to use a petri dish/plate pack that has been diluted to this concentration. Adjusting the coating concentration according to your specific experimental needs is essential for optimal results.
2) Coated cell culture plates under aseptic conditions, using 0.5mL-1.0ml /25cm2.Gently shake the bottom of the board to cover the entire surface.
3) After 5min, the surface solution of the culture plate was removed with a gun, and the surface of the culture plate was cleaned with sterile tissue culture grade water or PBS;Note: In some cases, it takes 1~2 hours to complete the planking, sometimes overnight planking is needed.It depends.
4) Cell culture can be carried out after drying for at least 2h.
Note: If the coated glassware or glass slides need to be sterile, γ-ray irradiation (rather than autoclastic sterilization) can be used to sterilize them.
3. Histological study (cover of glass slides)
0.1% (w/v) Poly-D-Lysine solution is generally recommended for the preparation of histological slides.After the slides were treated with the corresponding concentration of polylysine solution for 5min, the slides were washed and dried overnight at room temperature or in an oven at about 60° C for 1h.Note: This working solution is stored in a plastic bottle at 4° C, and is limited to 4 times of use.

Store at -20°C and keep dry for 3 years.

Poly-D-lysine (Mw 150,000-300,000)

Solid

Soluble in water